Page Six reports that Shark Tank's Daymond John, 47, is engaged to longtime girlfriend Heather. John proposed on the set of his show Shark Tank. Also present for the proposal? The couple's six-month-old daughter Minka, along with John's Shark Tank co-stars Mark Cuban, Barbara Corcoran, Robert Herjavec, Kevin O’Leary and Lori Greiner. Heather is now sporting a 9.5 carat emerald-cut diamond ring.